In recent years the ability of thieves to take vehicles without consent has substantially diminished, principally due to sophisticated electronic immobilizers which rely upon the presence or insertion of an enabling device, typically an ignition ‘key’. Thus without the key, drive away of a vehicle is not possible.
As a consequence vehicle theft now relies upon obtaining the ignition key, typically by confronting the vehicle driver at the vehicle. An alert driver in a stationary vehicle may be able to observe the approach of suspicious persons, and take action by driving away.
Electric vehicles, hybrid vehicles and other vehicles reliant upon a charging station are however vulnerable since the vehicle is generally adapted to be immobilized (through immobilizing the engine/motor/transmission) whilst connected to the charging station. In such circumstances the vulnerable vehicle can be both readily identified, by proximity to the charging station, and the vehicle driver is prevented from immediately driving away upon noticing a threat. Immobilization is typically provided by means of a sensor, which is provided to sense the presence of a connector of a charging lead on the vehicle. Such a sensor may be mechanical or electrical and operate to both immobilize the vehicle and enable transfer of energy via the charging lead. Vehicle immobilization is typically provided by preventing engagement of a drive condition of a transmission, but could alternatively directly disable a vehicle propulsion unit.
The connection of a charging lead to the vehicle immediately enables an engine or transmission immobilizer to prevent drive-away, and is considered to be an appropriate safety feature. Any kind of vehicle immobilizer is suitable for this purpose. A difficulty arises however that this safety feature may also render a vehicle and/or driver vulnerable to theft, since it may be possible for a thief to insert a device into vehicle charging socket for the purpose of rendering the vehicle immobile. In such circumstances the vehicle driver cannot drive away.
Therefore, in some circumstances it may be possible for a thief to change the state of the sensor and thereby disable the vehicle when not connected to a charging station. For example a thief may disable a vehicle which is parked or temporarily stopped, by shorting an electrical latch or by directly tampering with a mechanical latch.
It is against this background that the present invention has been conceived. Embodiments of the invention may provide a means of countering the theft threat of changing the state of such an immobilization system. Embodiments of the invention may also provide a means of countering a theft threat whilst a vehicle is connected to a charging station or charging point. Other aims and advantages of the invention will become apparent from the following description, claims and drawings.